1. Technical Field
The present invention relates to a method of manufacturing a semiconductor device and, more particularly, to a method of manufacturing an inductor using a system-in-package (SIP).
2. Related Art
A semiconductor device, such as a radio frequency (RF) device, may include a plurality of circuit elements, such as a transistor, an inductor, a capacitor, a resistor, and a varactor. Among them, the inductor may be considered as being necessary in an RF chip.
The inductor, as a single device, often occupies the largest area in the RF chip. Because the RF chip should be highly integrated with the circuit elements, the area occupied by the inductor needs be minimized, while maintaining the inductance value of the inductor.
In a passive circuit element, such as the inductor, a characteristic coefficient (Q) and a self-resonant frequency (fωo), which are the main characteristic factors of the inductor, decrease due to an undesired parasitic resistance and an undesired parasitic capacitance. Accordingly, the characteristics of the passive circuit element may deteriorate when applied to an RF integrated circuit (IC).
In order to prevent the main characteristic factors of the inductor from decreasing, it is important to reduce the parasitic resistance and the parasitic capacitance. Accordingly, when the inductor is manufactured, the parasitic resistance and the parasitic capacitance can decrease by forming a metal wiring using a metal of low resistance (e.g., gold (Au)), increasing the thickness of the metal wiring, or increasing the thickness of a dielectric film.
However, in a conventional semiconductor device manufacturing process, it is difficult to prevent the above situation, because a metal film is formed with a large thickness when manufacturing the inductor. In particular, because a transistor and a metal wiring are also formed on a substrate on which the inductor is formed, a process condition is complicated. In addition, when the inductor is erroneously formed, other elements formed on the substrate cannot be used.
When there is a current flowing in the inductor, a magnetic field is induced. The magnetic field may influence the current flowing in the metal wiring located below the inductor. Because the inductor may also serve as a resistor, there is thus a huge influence on the performance of the semiconductor device due to the existence of the induced magnetic field.